1. Field of the Invention
This invention relates to plastic wads for shotgun shells or the like.
2. Description of the Prior Art
It is known to make one piece shot holders and wads for shot shells of a flexible, deformable material such as molded plastic resin, for example polyethylene. The wad is spaced from the shot holder and connected thereto by some type of cushioning means.
The plastic shot holders protect the shot pellets from abrasion against the gun barrel, protect the pellets against deformation by being forced against the hard surface of the barrel, carry the shot pellets as a concentrated unit out of the gun barrel, and separate readily from the shot pellets soon after they leave the barrel. The wad portion is generally provided with a skirt which deforms outwardly against the gun barrel to inhibit passage of the expanding gases of the burning powder charge past the wad. The cushion between the wad and the shot holder cushions the impact of the expanding gases from the powder charge on the shot pellets to prevent the pellets from being deformed.
Various types of cushioning devices have been employed in the prior art. These devices include collapsable vertical walls located around the periphery of the wad, diagonal struts, crossed support walls, foam cushions and air chambers. Although all of these devices provide a cushion effect, they do not function with equal effectiveness. A major problem to be overcome is that the cushioning should be accomplished without tilting the wad, which might break the gas seal and cause transverse deflection of the wad and possibly the shot holder, not only within the gun barrel but also to the extent of interfering with the trajectory of the shot as it leaves the barrel.
Most wad designs also include a skirt which extends from the wad and contacts the gun barrel. The gas pressure of the powder charge will expand the skirt of the wad to form a gas seal. Generally, the skirt is tapered outwardly and rearwardly so that its own resilience and memory forces it into tight engagement with the shot shell casing wall to prevent initial leak of the expanding gases. Any gases escaping past the wad will not only lessen the muzzle velocity of the shot leaving the gun barrel, but will also pass through the shot in the holder to disturb the shot pattern.
It is a primary object of the present invention to provide a plastic shot shell wad which has an improved cushioning effect in comparison with the prior art.